Heat exchangers



Dec. 16, 1969 F. M. HEYN ET AL 3,483,920

HEAT EXCHANGERS Filed Jan. 29, 1968 2 Sheets-Sheet 1 Dec. 16, 1969 F. M.HEYN ET AL HEAT EXCHANGERS 2 Sheets-Sheet 2 Filed Jan. 29, 1968INVENTORS United States Patent Office 3,483,9Z Patented Dec. 16, 19693,483,920 HEAT EXCHANGERS Fred M. Heyn, Export, and Stanley J. Kletch,In, Bridgeville, Pan, assignors to Thermal Transfer Corporation FiledJan. 29, 1968, Ser. No. 701,243

Ciaims priority, application Germany, Oct. 13, 1967,

Int. Ci. FZSd 7/00; F28f 1/00 US. Cl. I65-I65 9 Claims ABSTRACT OF THEDISCLOSURE A heat exchanger is provided having tubes arranged inlatticed pattern and serving to conduct a medium to be heated or cooled,the ends of said tubes being held in end walls and the heating orcooling gas flowing through the exchanger transversely to thelongitudinal direction of the tubes.

This invention relates to heat exchangers and particularly to a heatexchanger having tubes Which are arranged in a latticed pattern andserve to conduct the medium that is to be heated or cooled, the ends ofsaid tubes being held in end walls, and the heating gas flowing throughthe heat exchanger vertically to the longitudinal direction of thetubes.

There are known heat exchangers in which parallel tubes are combinedinto tube bundles, the ends of the tubes being held in end walls whichrun parallel to one another and vertically to the longitudinal directionof the tubes. Tubes arranged in a latticed pattern are also known(Chemie-Ingenieur-Technik 1964, pages 247-260) in which the ends of thetubes are set into corresponding side walls.

It is the purpose of the invention to create a heat exchanger of thetype mentioned in the introduction by means of which it will be possibleto increase the transfer of heat and to reduce the pressure losses. Theinvention is further intended to create favorable heat transferconditions from the one medium to the other medium, in particular toafford possibilities for variations in order to produce variations inthe rate of flow of the medium which is to be heated or cooled andaccordingly in the velocity of flow of the medium, thereby varying theexchange of heat. The ratio of the heat transfer efficiency to the sizeof the structure is to be a favorable one.

To achieve this aim, the invention provides a heat exchanger of theabove mentioned type in which the ends of the tubes in accordance withthe invention are held in a polygonal or round frame which is open ontwo sides, at at least one tube end being connected to an adjacent tubeend in the same frame wall by means of an elbow, a chamber, or the like,and/or the frame being disposed in a cylinder or box-shaped housinghaving an inlet and an outlet for the medium which is to be heated orcooled, and the said frame on its inside wall abutting snugly against orbeing connected to two diametrically opposed edges or longitudinallines. The disposition of the frame in the housing is so designed thatthe medium that is to be heated or cooled will be split up so that oneportion of the medium which is to be heated or cooled will flow throughone portion of the tubes while the other portion of the medium that isto be heated or cooled will be guided through tubes disposed at rightangles to the first mentioned tubes. The frame with its tubes togetherwith the inside wall of the housing or box form a distribution chamberand a similar collector chamber, the cold or heated medium beingconducted in conventional manner by way of an inlet to the distributionchamber and being wi hdrawn from the collector chamber by way of anoutlet. For this purpose the frame is disposed on the inside wall of thehousing in a vertical or approximately vertical plane to the influent oreffluent direction of flow of the medium that is to be heated or cooled.Thus, no supplementary inlet and distribution chamber, nor acorresponding collector and outlet chamber are any longer required,since the housing forms these chambers in the manner described above. Inthis arrangement the frame is not only impermeably joined to the innerwall of the housing at its opposed edges or longitudinal lines, but italso abuts snugly with its longitudinal ends against both floors of thehousing or box in which the inlet and outlet ports are provided for theheating gas which flows through the housing at right angles to the rowsof tubes.

By using elbows or chambers on the ends of the tubes it is possible toallow the medium that is to be heated or cooled to pass through anydesired number of tubes preferably in the same row. In other words, thepath of the medium that is to be heated can be varied as desiredaccording to the requirements, it being necessary to equip only aportion of the tubes with elbows or chambers at their ends, anotherportion being left without any such elbows or chambers.

Thus, for example, those tubes of the tube bundle formed by the rows oftubes and the frame which are the first tubes in the direction of flowmay be Without such elbows or chambers at their ends, while tubesdisposed behind these first tubes in the direction of flow may beequipped with elbows or chambers positioned at their ends.

In the actual embodiment the frame is square and the housing round, orvice versa.

In another preferred embodiment of the invention the frame is subdividedinto smaller frame segments connected to their adjacent frame segmentsby means of flanges. These flanges carry sealing members in order toproperly seal off the frame in the housing and to form the previouslydescribed distribution and collector chambers for the medium that is tobe heated. Thus the same frame segments may be used in different numbersfor housings of different sizes.

Preferably the housing may also be subdivided into sections or segmentsnot only to facilitate the assembling of the recuperator, but also topermit a recuperator to be erected in any desired size on the principleof unit construction.

The tubes may be held in the Walls of the square, round, or oval framein conventional manner to allow for expansion of the tubes. For example,the tubes may be held in the frame walls by means of compensators orexpansion joints, as is already known to the art.

In the drawings exemplifying embodiments of a heat exchanger accordingto the invention are shown with their essential parts.

FIGURE 1 shows a box-shaped frame With the tubes lying in rows at rightangles to one another;

FIGURE 2 shows an elbow for the tube ends which serves as a transfermember;

FIGURE 3 is a schematic showing a possible path of travel through theframe for the medium that is to be heated and for the heating gases, andshows the tubes of two rows of tubes which are disposed at right anglesto one another;

FIGURE 4 shows two frame segments which may be assembled into one frameas in FIGURE 1;

FIGURE 5 shows a tube equipped frame within a housing, in other words, across-section through one embodiment of an exchanger according to theinvention;

FIGURE 6 is a side elevation of the heat exchanger shown in FIGURE 5;and

FIGURE 7 is another embodiment using a drumtype frame and a box-shapedhousing.

With reference to FIGURE 1, the tubes of the heat exchanger of theinvention are held at their ends by a frame 100 formed by walls 1, 2, 3,and 4. The tubes are arranged in rows in such a manner as to formhorizontal rows A, B, C F and vertical rows S, T, U Z. Thus, the tubesof these rows of tubes lie adjacent to one another and above one anotherin the same direction and also parallel to one another, and they allextend from the one frame Wall 1 to the parallel frame wall 3.

At right angles to the said rows of tubes, horizontal tubes rows G, H, IL extends from frame wall 2 to frame wall 4 and simultaneously formvertical rows M, N, O R. The rows of tubes in walls 1 and 3 arepositioned either higher or lower than the rows of tubes in walls 2 and4 in such a manner that the tubes of the corresponding rows of tubescross either above or below one another, as illustrated in FIGURE 1 withreference to the first two rows of tubes, row A and row G.

The medium that is to be heated or cooled may be conducted through theindividual tubes and rows of tubes as desired. In order to turn themedium that is to be heated or cooled around elbows 5 may be used whichform a bridge between the two ends of adjacent tubes. For example, anelbow may connect tube end 6 of tube 7 to tube end 8 of tube 9 when themedium that is to be heated or cooled is fed into tube 7 in thedirection indicated by arrow 10. However, end 6 of tube 7 may also beconnected to end 11 of the tube disposed below tube 6. In similar mannerany desired number of tubes may be connected to their adjacent tubes,thus making the path of the medium which is to be heated either long orshort. In the direction of flow of the heat transmitting medium (arrow12 in FIGURE 1), the first tubes may be connected differently to oneanother at their ends than the tubes which are disposed outside of theframe at the discharge end of the heating gas or the cooling agent.

FIGURE 3 is a schematic illustration of the path of travel of theheating gas or cooling agent and of a partial stream (or flow) of themedium that is to be heated or cooled. The heating gas or coolant flowsin the direction of arrow 12 and flows out in the direction of arrow 21.One partial stream of the medium that is to be heated or cooled flows inthe direction of arrow 14 into first tube 15, by way of elbow 16 intotube 17 disposed therebelow, from tube 17 into tube 18 and finally intotube 19 and emerges from the pipeline at 20. A second partial stream mayflow in the direction of arrow 22 into tube 23 and reach tube 25 by wayof elbow 24. This partial stream is led off in the direction of arrow26. Tubes and 23 are connected to two entry collectors, while tubes 19and are connected to two exit (or discharge) collectors.

In order to form the frame shown in FIGURE 1, a number of frame segments28 may be used. These segments are provided with flanges 30 by means ofwhich the frame segments may be joined to one another. In these framesegments the rows of tubes also run at right angles to one another, thusagain providing a crosswise arrangement of successive tubes in thedirection of flow of the heating gas or coolant (direction of flow ofthe heating gas or coolant is indicated by arrows 31 in FIGURE 4).

A tube-equipped frame 100 or a frame composed of box members 28 is setinto a housing 32 as shown in FIGURES 5 and 6. This housing is equippedwith a discharge duct 33 for the medium that is to be heated or cooled.Frame 100 is mounted in housing 32 in such a way that the diametricallyopposed longitudinal edges 34 and 35 of the frame abut tightly againstthe interior wall of the cylindrical housing and are held in seal-tightmanner by approximately W-shaped holders 36 which extend over the heightand length of the box. Edges 37 and 38 of the frame (FIGURE 6) aresealed 01f against ends 39 and 40 of the housing at 41. No connection isrequired since the frame is held in the housing by its longitudinaledges 34 and 35. Ends 39 and 40 are provided with inlet 42 and outlet43, respectively for the heating gas or cooling agent that flows intoframe through the pipe lattice in the direction of arrows 52.

The square frame and cylindrical housing 32 form two distributionchambers, 45 and 46, and two collector chambers 47 and 48 into whichinlet duct 29 and outlet duct 33 open. From distribution chamber 45 themedium that is to be heated or cooled enters tubes 49 while fromdistribution chamber 46 the medium that is to be heated or cooledflows.into tubes 50 disposed vertically thereto. Both the inflow fromthe distribution chambers into the said tubes as well as the outflowfrom these tubes into the discharge pipe 'of outlet duct 33 is greatlyenhanced by the position of the tubes in relation to the curvature andby the said curvature of the walls of housing 32.

The flow through tubes 49 and 50 may be varied as desired, as hasalready been explained in connection with the description of the frameshown in FIGURE 1. Theelbows 5 shown in FIGURE 2 may be-used as desiredfor this purpose. Without changing the housing'or the frame it ispossible to alter the manner of the flow as desired, i.e. the length andvelocity of the flow and thereby the heat transmission and also thepressure ratios. In view of the added advantage of being able toassemble both frame 100' and the housing from individual members. thuspermitting unit construction, there are indeed many possibilities forvariations in the construction of the heat exchanger.

When using frame segments 28 shown in FIGURE 4, seals 51 are mountedbetween the flanges 30 of a box member on its diametrically opposededges. These seals will abut against W-shaped members 36 in housing 32.

In the embodiment shown in FIGURE 7 the same principle is used wherebytubes are arranged in criss-cross pattern in a drum-shaped frame 60disposed in a boxshaped housing 61 whose upper side 62 and lower sideare provided with an inlet and an outlet for the medium which is flowingin or out in the direction of arrows 63 and which is absorbing oremitting heat (heat gases in the tube). Drum 60 is again impermeablyconnected to the inner wall of housing 61 at two diametrically opposedlines 64, just as the annular bands 65 of the drum abut sealinglyagainst the two floors 66 of housing 61. Inlet and outlet ports areprovided in these floors for the heating gas or cooling agent whichflows through frame 60 in the direction of arrows 67. To avoid confusionthe inlet and outlet for the heating gas or the coolant in floor 66 arenot shown.

In the embodiment shown in FIGURE 7 the drumshaped frame 60 may alsoconsist of a number of discshaped individual members which are joinedtogether by means of flanges in a manner similar to that employed withframe members 28 of FIGURE 4. Housing 61 may also be constructed of aplurality of members connected by means of flanges just as, for example,the two segments of housing 32 are joined together by means of flanges68. Similarly, the embodiment of FIGURE 7 may also be varied by applyingthe principle of unit construction, the ends of the tubes beingconnectable with one another by means of elbows just as is the case withthe tubes of frames 100 shown in FIGURES l and 6.

The heat exchanger of the invention can also be developed as anindirectly heated heater, for which purpose the air that is to beheated, i.e. the compressed air that is to be heated, is conductedthrough the tubes and the tubes are heated by the flames or the gases ofa burner.

In the foregoing specification I have set out certain preferredembodiments of my invention, however, it will be understood that thisinvention may be otherwise embodied within the scope of the followingclaims.

We claim:

1. A heat exchanger comprising a plurality of tubes arranged in at leasttwo side-by-side planes to carry at least one fluid for heat exchange,the tubes in one plane being transverse to those of the other plane,said tubes being held at their ends in the sidewalls of one of apolygonal and a round frame open at the two sides transverse to thesidewalls to form an inlet and outlet for a second fluid for heatexchange, and a housing surrounding said frame and having an inlet andoutlet, said housing engaging the frame to form with the said housinginlet and outlet a flow path for said at least one fluid through theplurality of tubes in said two side-by-side planes.

2. A heat exchanger as claimed in claim 1 wherein the tubes in said twoplanes are at substantially right angles to one another.

3. A heat exchanger as claimed in claim 1 wherein the frame is connectedto the housing along diametrically opposed edges.

4. A heat exchanger as claimed in claim 1 wherein the frame is connectedto the inner wall of the housing in a plane substantially transverse tothe direction of flow in the tubes.

5. A heat exchanger as claimed in claim 1 wherein the frame is square incross-section and the housing is round in cross-section.

6. A heat exchanger as claimed in claim 1 wherein the frame is round incross-section and the housing is square in cross-section.

7. A heat exchanger according to claim 1 wherein a plurality of frameseach carrying tubes in multiples of at least two side-by-side planes,said frames being joined by means of flanges.

8. A heat exchanger according to claim 7 wherein the housing isassembled in units corresponding to the individual frames connectedtogether.

9. A heat exchanger with tubes arranged in a crossshaped pattern,characterized by the fact that the ends of the tubes are held in thesidewalls of a frame that is open on two sides transverse to thesidewalls to form an inlet and outlet for one heat exchange fluid, andthat at least one tube end is connected to an adjacent tube end in thesame wall of the frame and that the frame is disposed in a housinghaving an inlet and an outlet for a second heat ex change fluid that isto be heated or cooled, the frame being connected to the inner edge ofthe housing at two diametrically opposed edges to form a connectionbetween the inlet and one end of said tubes and the outlet and the otherend of said tubes.

References Cited UNITED STATES PATENTS 1,571,068 1/1926 Stanclifle165--16S 2,317,572 4/1943 Whitt et al 165165 X 2,887,303 5/1959 Reys165165 X 3,315,739 4/1967 Kearney 165-465 FOREIGN PATENTS 1,368,4546/1964 France.

ROBERT A. OLEARY, Primary Examiner T. W. STREULE, Assistant ExaminerU.S. Cl. X.R. 165-157

